U.S. patent application number 10/886087 was filed with the patent office on 2005-03-03 for apparatus for manufacturing band plate.
This patent application is currently assigned to Ishikawajima-Harima Heavy Industries Co., Ltd.. Invention is credited to Honjo, Hisashi, Iwasaki, Takayuki.
Application Number | 20050044916 10/886087 |
Document ID | / |
Family ID | 34213277 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050044916 |
Kind Code |
A1 |
Honjo, Hisashi ; et
al. |
March 3, 2005 |
Apparatus for manufacturing band plate
Abstract
An apparatus for manufacturing a band plate has a rolling mill
that includes a pair of upper and lower work rolls that roll a slab
material having edge drop portions at both ends thereof, and a pair
of backup rolls that contact non-rolling side surfaces of the pair
of upper and lower work rolls, respectively to prevent the work
rolls from being deformed. The work roll includes a reverse taper
portion where a roll diameter gradually increases towards a barrel
end portion thereof corresponding to the edge drop portion. The
upper and lower work rolls are configured to be shiftable
individually in the axial direction thereof. The backup roll
includes an escape portion whose diameter gradually decreases
towards an axial end thereof so as not to contact the reverse taper
portion of the work roll, within a shifting range of the work
roll.
Inventors: |
Honjo, Hisashi; (Chiyoda-ku,
JP) ; Iwasaki, Takayuki; (Chiyoda-ku, JP) |
Correspondence
Address: |
GRIFFIN & SZIPL, PC
SUITE PH-1
2300 NINTH STREET, SOUTH
ARLINGTON
VA
22204
US
|
Assignee: |
Ishikawajima-Harima Heavy
Industries Co., Ltd.
Chiyoda-ku
JP
|
Family ID: |
34213277 |
Appl. No.: |
10/886087 |
Filed: |
July 8, 2004 |
Current U.S.
Class: |
72/243.6 |
Current CPC
Class: |
B21B 2013/025 20130101;
B21B 13/142 20130101; B21B 29/00 20130101; B21B 2269/14 20130101;
B21B 1/026 20130101; B21B 2263/02 20130101; B21B 27/02 20130101;
B21B 1/463 20130101; B21B 2269/04 20130101; B21B 2027/022 20130101;
B21B 2001/028 20130101 |
Class at
Publication: |
072/243.6 |
International
Class: |
B21B 029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 4, 2003 |
JP |
2003-286014 |
Claims
1. An apparatus for manufacturing a band plate, comprising a
rolling mill that includes: a pair of upper and lower work rolls
that roll a slab material having edge drop portions at both ends
thereof, and a pair of backup rolls that contact non-rolling side
surfaces of the pair of upper and lower work rolls, respectively to
prevent the work rolls from being deformed, wherein the work roll
comprises a reverse taper portion where a roll diameter gradually
increases towards a barrel end portion thereof corresponding to the
edge drop portion, the upper and lower work rolls are configured to
be shiftable individually in the axial direction thereof, and the
backup roll comprises an escape portion whose diameter gradually
decreases towards an axial end thereof so as not to contact the
reverse taper portion of the work roll, within a shifting range of
the work roll.
2. The apparatus for manufacturing the band plate, according to
claim 1, wherein the work roll comprises a cylindrical expansion
diameter portion outside the reverse taper portion, and the backup
roll comprises a cylindrical contraction diameter portion that
contacts the expansion diameter portion, outside the escape
portion.
3. The apparatus for manufacturing the band plate, according to
claim 1, further comprising a work roll bending mechanism that
applies a bending moment to the work roll to finely adjust a crown
during rolling.
4. The apparatus for manufacturing the band plate, according to
claim 1, further comprising a strip caster at a downstream side of
which the rolling mill is provided.
5. The apparatus for manufacturing the band plate, according to
claim 2, further comprising a strip caster at a downstream side of
which the rolling mill is provided.
6. The apparatus for manufacturing the band plate, according to
claim 3, further comprising a strip caster at a downstream side of
which the rolling mill is provided.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field of the Invention
[0002] The present invention relates to an apparatus for
manufacturing a band plate that presses edge drop portions at both
ends of a plate before rolling, together with a center part of the
plate, and leaves edge drops on the plate after rolling.
[0003] 2. Description of the Related Art
[0004] FIGS. 1A and 2 are schematic views of a continuous casting
machine of a double-roll type. As shown in these figures, when a
slab of a predetermined width is manufactured using a continuous
casting machine 50 (strip caster), casting metal in a molten state
is passed through two rolls 51 (casting rolls) that rotate in
reverse directions. Casting rolls 51 are separated by a
predetermined gap that is appropriate for forming the thickness of
a slab plate, and are installed in parallel and horizontally.
[0005] Molten metal for casting is supplied to a pouring basin
formed between side dams 53 disposed between both ends of the
casting rolls and a top portion of outer peripheries of casting
rolls 51, from an opening of a flat-shaped nozzle 52 of a tundish
arranged immediately above (top portion of) the two casting rolls
51. Both side dams 53 are disposed to match the width of the slab
to be manufactured, and to prevent molten metal from leaking onto
the side surfaces of the ends of casting rolls having the same
length as the width of the slab.
[0006] The continuous casting machine 50 of a double-roll type
manufactures a slab with a predetermined approximate width of 1,200
to 2,000 mm. The continuous casting equipment of a double-roll type
can operate using simple ancillary equipment in a compact layout
compared to other continuous casting apparatus such as
caterpillar-type continuous casting equipment.
[0007] When a slab material that has been manufactured with double
rolls or a single roll is rolled by a rolling mill 56 downstream on
the line, the rolling mill is a conventional non-shifting mill,
instead of using a rolling mill in which rolls are shifted in the
axial direction of the roll. Conventionally, a roll of the rolling
mill has a shape of a parabolic or sinusoidal curve, and have
diameters larger at the axial center of the roll than at the ends
(barrel-shaped rolls). Barrel-shaped rolls are widely used in a
conventional rolling mill to compensate for warping of the pressing
roll.
[0008] However, the aforementioned continuous casting machine 50 of
a double-roll type suffers from a heat crown phenomenon at the
casting rolls during casting, because of the long casting roll 51.
As a result of this heat crown phenomenon, casting conditions vary
along the width of the casting roll. In particular, the variation
at the width ends of the work roll becomes greater. Therefore, at
the position nearer to the width ends of the roll, the distribution
of a plate thickness in the lateral (width) direction of a slab
varies more largely.
[0009] In addition, because side dams 53 are disposed at both ends
of the rolls, heat dissipation efficiencies are high at the roll
surfaces that are in contact with side dams; along a lateral
section of the slab, portions close to the roll width ends are
cooled more efficiently than at the center, so the plate thickness
changes from the center to the width ends, resulting in a concave
or convex shape. As a result, as shown in FIG. 1B for instance, the
section of the slab is tapered at both ends; or conversely, the
thickness of the slab may increase at both ends. In the following
description, the sectional shape of a slab with tapered ends is
called an "edge-drop crown," and the shape with elevated ends is
called an "edge-up crown."
[0010] The inventors of the present invention have already invented
a technique and applied it for a patent. This technique is
described in Patent literature 1 correcting the edge drop or up
crown described above. Patent literature 1 "Band plate
manufacturing apparatus" discloses a continuous casting machine of
a double-roll or single-roll type, that continuously casts a slab
of a predetermined width with molten metal for casting, supplied
from a tundish arranged at an upstream location, and a single
finish rolling mill that is disposed downstream of the continuous
casting machine, and is provided with a pair of up/down work rolls
that can move along the axes thereof in opposite directions. As
shown in FIG. 3, each of the upper and lower work rolls 61, 62 is
shaped for the roll crown such that a diameter of the work roll is
made to decrease over a part to one end of the work roll from a
position separated by 200 mm from the one end of the work roll, and
a diameter of the work roll is made to increase over a part to the
other end of the work roll from a position separated by 200 mm from
the other end of the work roll. In addition, the work roll profile
(outline) between the diameter-changing points is formed as a
straight line or an united shape of the straight line and a center
convex shape. In other words, each work roll 61 or 62 is a ground
crown roll. In addition, both rolls with the roll crown described
above are disposed point-symmetrically about a rolling center such
that the diameter-decreasing and diameter-increasing part of the
upper work roll are respectively positioned at opposite sides of
the diameter-decreasing and diameter-increasing part of the lower
work roll.
[0011] [Patent Literature 1]
[0012] Japanese Laid-Open Patent publication No. 11503, 2002
[0013] As described above, a plate to be rolled by a rolling mill
may have a large edge drop. In particular, a strip caster often
produces large edge drops, so slabs manufactured therewith must be
specially processed.
[0014] Furthermore, edge drops produced by a strip caster can often
differ at both ends, because molten metal solidifies differently
near both side dams. Therefore, a means for controlling edge drops
in a way that differs for left and right side portions is
required.
[0015] Generally, if the edge drops of a raw material is large and
the material is rolled so deeply that edge drops are eliminated,
the elongation ratio at a center portion, originally free from edge
drops, becomes excessively high, resulting in a problem of
undulation produced at the center portion. Therefore, as shown
typically in FIG. 4, it is required that both center portion and
edge drop portions are rolled so as to leave the edge drops at both
end portions after rolling. In FIG. 4, "BEFORE ROLLING" indicates a
shape of the plate before rolling, and "AFTER ROLLING" indicates a
shape of the plate after rolling.
SUMMARY OF THE INVENTION
[0016] The present invention aims to cope with these requests. That
is, an object of the present invention is to provide an apparatus
for manufacturing a band plate that can roll respective edge drops
together with the center portion, leaving edge drops after rolling,
even in a case of large edge drop portions in a plate before
rolling and sizes of edge drops that differ between left and right
edges of the plate.
[0017] According to the present invention, there is provided an
apparatus for manufacturing a band plate, comprising a rolling mill
that includes: a pair of upper and lower work rolls that roll a
slab material having edge drop portions at both ends thereof; and a
pair of backup rolls that contact non-rolling side surfaces of the
pair of upper and lower work rolls, respectively to prevent the
work rolls from being deformed, wherein the work roll comprises a
reverse taper portion where a roll diameter gradually increases
towards a barrel end portion thereof corresponding to the edge drop
portion, the upper and lower work rolls are configured to be
shiftable individually in the axial direction thereof, and the
backup roll comprises an escape portion whose diameter gradually
decreases towards an axial end thereof so as not to contact the
reverse taper portion of the work roll, within a shifting range of
the work roll.
[0018] According to a preferred embodiment of the present
invention, the work roll comprises a cylindrical expansion diameter
portion outside the reverse taper portion, and the backup roll
comprises a cylindrical contraction diameter portion that contacts
the expansion diameter portion, outside the escape portion.
[0019] Preferably, the apparatus for manufacturing the band plate
further comprises a work roll bending mechanism that applies a
bending moment to the work roll to finely adjust a crown during
rolling.
[0020] Preferably, the apparatus for manufacturing the band plate
further comprises a strip caster at a downstream side of which the
rolling mill is provided.
[0021] According to the aforementioned configuration of the present
invention, because the work roll is provided with the reverse taper
portion, on which roll diameters gradually increase towards the
barrel end portion thereof corresponding to the edge drop part, and
the upper or lower work roll is composed to be shiftable
individually in the axial direction of the roll, even if edge drops
at both ends of the slab material differ greatly from each other,
the shape of the rolled plate can be maintained under the preferred
conditions by separately axially shifting the upper and lower work
rolls.
[0022] Also, because the backup roll is provided with the escape
portion at which roll diameters gradually decrease towards an end
of the axis of the roll within the shiftable range of the work
roll, so that the backup roll does not come into contact with the
reverse taper portion of the work roll, the reverse taper portion
of the work roll can be prevented from interfering with the backup
roll, so the work roll can be axially shifted with a small
resistance.
[0023] In addition, the crown can be finely adjusted during
rolling, by applying a bending moment to the work roll by means of
the work roll bending mechanism etc.
[0024] Other objects and advantages of the present invention are
revealed as follows, referring to the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0025] FIGS. 1A and 1B are schematic views of a conventional
continuous casting machine of a double-roll type.
[0026] FIG. 2 is another schematic view of the conventional
double-roll-type continuous casting machine.
[0027] FIG. 3 typically shows the "Band Plate-Manufacturing
Apparatus" according to Patent literature 1.
[0028] FIG. 4 shows a preferred state of rolled edge drops.
[0029] FIG. 5 illustrates the first embodiment of the apparatus for
manufacturing a band plate according to the present invention.
[0030] FIG. 6 shows another state of the apparatus shown in FIG.
5.
[0031] FIG. 7 shows the state of the second embodiment of the
apparatus for manufacturing a band plate according to the present
invention.
[0032] FIG. 8 is a view showing another operating state of the
apparatus in FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Preferred embodiments of the present invention are described
below referring to the drawings. In each drawing, common parts and
components are identified with the same numbers, while omitting any
duplicate descriptions.
[0034] FIG. 5 shows the first embodiment of the apparatus for
manufacturing a band plate according to the present invention; FIG.
6 shows another operating status of the apparatus in FIG. 5.
[0035] The apparatus for manufacturing a band plate of the present
invention is preferably provided with a rolling mill 10 arranged
downstream from a strip caster. In FIG. 5, this rolling mill 10 is
composed of a pair of upper and lower work rolls 20 and a pair of
upper and lower backup rolls 30.
[0036] The work roll 20, in a pair of upper and lower rolls, is
provided with a rolling portion 22 formed in a slim cylinder, and
can press a slab material 1 with edge drop portions 2 at both ends
thereof. The backup roll 30, in a pair of upper and lower rolls, is
shaped to have a backup portion 32 in a small cylinder, and
contacts the non-rolling side surface of the work roll 20 in the
pair, and can protect the work roll 20 from being bent and
deformed. The backup roll 30 is supported by bearings, illustrated
as triangles in FIG. 5, at both ends thereof in a rotatable
manner.
[0037] In FIG. 5, the work roll 20 is sequentially composed of a
reverse taper portion 24 and the expansion diameter portion 26 at
the barrel end part of the cylindrical rolling portion 22. The
reverse taper portion 24 is positioned at the barrel end part
corresponding to the edge drop 2 of the slab material 1, and has a
reverse taper in which the diameter gradually increases towards the
axial end. The expansion diameter portion 26 is placed outside the
reverse taper portion, and has a cylindrical shape.
[0038] The upper and lower work rolls 20, as a pair, preferably has
the same shape and, as shown in FIG. 5, are disposed
point-symmetrically about the center of the rolling mill.
[0039] Both upper and lower work rolls 20 are configured to be
shiftable individually in the respective axial directions by means
of a roll shifting device, which is not illustrated but is shown by
the horizontal arrow marks.
[0040] Furthermore, as shown by the arrow marks in the vertical
direction of the roll, a work roll bending mechanism (not
illustrated) is incorporated at both ends of the work roll 20,
whereby the crown of the slab material 1 is finely adjusted during
rolling by applying the bending moment.
[0041] In FIG. 5, the backup roll 30 is shaped to have an escape
portion 34 and the contraction diameter portion 36, disposed
sequentially, at the barrel end part of the cylindrical backup
portion 32. The profile of the escape portion 34 has a taper as the
roll diameters gradually decrease towards the axial end such that
the escape portion 34 does not contact the reverse taper portion 24
of the work roll within a shiftable range of the work roll 20. The
contraction diameter portion 36 is located outside the escape
portion, and has a cylindrical shape.
[0042] A pair of upper and lower backup rolls 30 preferably have
the same shape. As shown in FIG. 5, they are arranged
point-symmetrically about the center of the rolling mill.
[0043] In this example, the expansion diameter portion 26 of the
work roll and the contraction diameter portion 36 of the backup
roll are arranged so as not to come into contact with each other.
In other words, the expansion diameter portion 26 and the
contraction diameter portion 36 are not functionally indispensable,
so they can be omitted from the configuration.
[0044] FIGS. 5 and 6 show medium-sized edge drop (called medium
edge drop) and large-sized edge drop (called large edge drop) of
work rolls, respectively in the above-mentioned rolling mill.
[0045] In FIG. 5, upper and lower work rolls 20 are shifted by a
small stroke corresponding to the medium edge drop, and roll a
center portion and edge drop 2 of slab material 1, at the same
time. In FIG. 6, the shift stroke of work rolls 20 is large in
proportion to the large edge drop, while simultaneously rolling the
center portion and edge drop 2 of slab material 1.
[0046] Rolling conditions of the slab center portion are adjusted
by a rolling load applied by backup rolls 30. Conditions for
rolling edge drop portions 2 are adjusted by the shifting stroke of
the work rolls, as well as the rolling load. In addition, the work
roll bending mechanism imposes a bending moment that finely adjusts
the crown of slab material 1 during rolling.
[0047] FIG. 7 shows the second embodiment of the apparatus for
manufacturing a band plate according to the present invention, and
FIG. 8 shows another operation state of the apparatus shown in FIG.
7.
[0048] In this embodiment, the expansion diameter portion 26 of the
work roll and the contraction diameter portion 36 of the backup
roll are in contact with each other. Therefore, in this example,
expansion and contraction diameter portions 26, 36 functions,
differently from the first embodiment. Other configuration details
are the same as those in the first embodiment.
[0049] FIG. 7 is a view in which shifting strokes of upper and
lower work rolls 20 are the same for this apparatus; and FIG. 8
represents a case where shifting strokes of upper and lower work
rolls 20 differ from each other.
[0050] In FIG. 7, like the operation state of the first embodiment,
the depth of rolling the center portion of the slab is adjusted by
the rolling load applied from the back up roll 30, and the depth of
the rolling of edge drop portion 2 is adjusted by the rolling load,
a shifting stroke of the work roll and work roll bending. In this
case, because the expansion diameter portion 26 of the work roll is
backed up by the contraction diameter portion 36 of the backup
roll, the effects of work roll bending are low at the expansion
diameter portion side and high at the opposite side.
[0051] In FIG. 8, the shifting strokes of upper and lower work
rolls 20 are different; in this embodiment, both rolls shift
leftwards in FIG. 8. As a result, even where edge drops 2 of slab
material 1 are small and large at the left and right sides, both
edges can be rolled at the same time. Other effects are the same as
those related to FIG. 7.
[0052] According to the configuration of the present invention, as
described above, because the work roll 20 is provided with a
reverse taper portion 24 at which diameters gradually increase
towards the barrel end part corresponding to edge drop 2, and the
upper and lower work rolls are configured such that they can
individually be shifted in the axial direction, even if the edge
drops at both ends of the slab material differ considerably from
each other, the shape of the rolled plate can be maintained in good
condition by separately shifting upper and lower work rolls in the
axial direction.
[0053] Because the backup roll 30 is equipped with the escape
portion 32 where diameters gradually decrease towards the axial end
so that the roll does not contact the reverse taper portion of the
work roll, the reverse taper portion of the work rolls can be
prevented from interfering with the backup roll, and the work roll
can be shifted axially with a low resistance.
[0054] In addition, the crown can be finely adjusted by means of a
work roll bending mechanism that applies a bending moment to the
work rolls.
[0055] The present invention should of course not be limited only
to the aforementioned embodiments, but can be modified in various
ways provided there are no deviations from the claims of the
present invention.
* * * * *